U.S. patent number 4,222,928 [Application Number 05/958,488] was granted by the patent office on 1980-09-16 for polyester composition.
This patent grant is currently assigned to Teijin Limited. Invention is credited to Takeo Kawamura, Teruo Matsunaga.
United States Patent |
4,222,928 |
Kawamura , et al. |
September 16, 1980 |
Polyester composition
Abstract
A novel polyester composition which can give shaped articles
being free from warping and having superior mechanical and thermal
properties. The polyester composition comprises (A) 100 parts by
weight of an aromatic polyester, (B) 5 to 150 parts by weight of
flat glass flakes, and based on the total weight of (A) and (B),
(C) 0.01 to 10% by weight of an epoxy compound containing two epoxy
groups, and optionally (D) 0.01 to 5% by weight of a phosphorus
compound and/or (E) 0.5 to 50% by weight of a rubbery elastomer
selected from the group consisting of copolymers containing 30 to
90% of an acrylic ester as a constituent monomer and
poly(ether.ester) elastomers. Up to half of the flat glass flakes
may be replaced by a powdery inorganic solid such as feldspar.
Inventors: |
Kawamura; Takeo (Sagamihara,
JP), Matsunaga; Teruo (Sagamihara, JP) |
Assignee: |
Teijin Limited (Osaka,
JP)
|
Family
ID: |
27297031 |
Appl.
No.: |
05/958,488 |
Filed: |
November 7, 1978 |
Foreign Application Priority Data
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Nov 9, 1977 [JP] |
|
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52-133583 |
Dec 15, 1977 [JP] |
|
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52-149905 |
May 22, 1978 [JP] |
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53-59890 |
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Current U.S.
Class: |
523/451; 525/107;
523/400; 525/438 |
Current CPC
Class: |
C08K
7/14 (20130101); C08L 67/02 (20130101); C08L
63/00 (20130101); C08K 7/00 (20130101); C08K
3/00 (20130101); C08K 7/14 (20130101); C08L
67/02 (20130101); C08L 67/02 (20130101); C08L
67/02 (20130101); C08L 63/00 (20130101); C08L
2666/02 (20130101) |
Current International
Class: |
C08K
7/14 (20060101); C08L 67/02 (20060101); C08L
67/00 (20060101); C08K 7/00 (20060101); C08L
063/00 (); C08L 067/00 () |
Field of
Search: |
;260/835,4R
;525/107,438 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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49-90345 |
|
Aug 1974 |
|
JP |
|
50-1146 |
|
Jan 1975 |
|
JP |
|
50-23449 |
|
Mar 1975 |
|
JP |
|
51-44160 |
|
Apr 1976 |
|
JP |
|
Primary Examiner: Lieberman; Paul
Attorney, Agent or Firm: Sherman & Shalloway
Claims
What we claim is:
1. A composition comprising (A) 100 parts by weight of an aromatic
polyester, (B) 5 to 150 parts by weight of flat glass flakes up to
one-half of which may be replaced by a powdery inorganic solid, and
(C) 0.01 to 10% by weight, based on the total weight of (A) and
(B), of an epoxy compound containing two terminal epoxy groups
selected from the group consisting of (i) diglycidyl polyether
(mono- to deca-mers) obtained by the reaction of
2,2-bis(4-hydroxyphenyl) propane (bisphenol A) with epichlorohydrin
and (ii) diglycidyl ether obtained by the reaction of a glycol with
epichlorohydrin.
2. A composition comprising (A) 100 parts by weight of an aromatic
polyester, (B) 5 to 150 parts by weight of flat glass flakes up to
one-half of which may be replaced by a powdery inorganic solid, (C)
0.01 to 10% by weight, based on the total weight of (A) and (B), of
an epoxy compound containing two terminal epoxy groups selected
from the group consisting of (i) diglycidyl polyether (mono- to
deca-mers) obtained by the reaction of 2,2-bis(4-hydroxyphenyl)
propane (bisphenol A) with epichlorohydrin and (ii) diglycidyl
ether obtained by the reaction of a glycol with epichlorohydrin,
and (D) 0.01 to 5% by weight, based on the total weight of (A) and
(B), of a phosphorus compound.
3. A composition comprising (A) 100 parts by weight of an aromatic
polyester, (B) 5 to 150 parts by weight of flat glass flakes up to
one-half of which may be replaced by a powdery inorganic acid, (C)
0.01 to 10% by weight, based on the total weight of (A) and (B), of
an epoxy compound containing two terminal epoxy groups selected
from the group consisting of (i) diglycidyl polyether (mono- to
deca-mers) obtained by the reaction of 2,2-bis(4-hydroxyphenyl)
propane (bisphenol A) with epichlorohydrin and (ii) diglycidyl
ether obtained by the reaction of a glycol with epichlorohydrin,
and (D) 0.5 to 50% by weight, based on the total weight of (A) and
(B), of a rubbery elastomer selected from the group consisting of
copolymers containing 30 to 90% of an acrylic ester as a
constituent monomer and poly (ether.ester) elastomers.
4. A composition comprising (A) 100 parts by weight of an aromatic
polyester, (B) 5 to 150 parts by weight of flat glass flakes up to
one-half of which may be replaced by a powdery inorganic solid, (C)
0.01 to 10% by weight, based on the total weight of (A) and (B), of
an epoxy compound containing two terminal epoxy groups selected
from the group consisting of (i) diglycidyl polyether (mono- to
deca-mers) obtained by the reaction of 2,2-bis(4-hydroxyphenyl)
propane (bisphenol A) with epichlorohydrin and (ii) diglycidyl
ether obtained by the reaction of a glycol with epichlorohydrin,
(D) 0.01 to 5% by weight, based on the total weight of (A) and (B),
of a phosphorus compound, and (E) 0.5 to 50% by weight of a rubbery
elastomer selected from the group consisting of copolymers
containing 30 to 90% of an acrylic ester as a constituent monomer
and poly(ether.ester) elastomers.
5. The composition of claim 1 wherein the flat glass flakes have a
long diameter of not more than 1000 microns and an aspect ratio of
at least 5.
6. The composition of claim 5 wherein the long diameter is from 1
to 500 microns and the aspect ratio is at least 10.
7. The composition of claim 2 wherein the flat glass flakes have a
long diameter of from 1 to 500 microns and an aspect ratio of at
least 10.
8. The composition of claim 3 wherein the flat glass flakes have a
long diameter of from 1 to 500 microns and an aspect ratio of at
least 10.
9. The composition of claim 4 wherein the flat glass flakes have a
long diameter of from 1 to 500 microns and an aspect ratio of at
least 10.
Description
This invention relates to a polyester composition, and more
specifically, to a polyester composition which gives shaped
articles free from warping and having superior mechanical and
thermal properties.
Attempts have been made in recent years to substitute engineering
plastics partly for component parts of automobiles, electrical
appliances, etc., and consequently, the demand for engineering
plastics, especially those reinforced with reinforcing materials,
has increased. One group of these engineering plastics includes
polyalkylene terephthalates, especially reinforced polyalkylene
terephthalate compositions.
Fibrous inorganic materials such as glass fibers have been widely
used as reinforcing materials for polyalkylene terephthalates.
Certainly, these fibrous inorganic materials are useful because
they increase the heat distortion temperatures of polyalkylene
terephthalates and improve their mechanical properties. But since
they have directionality, they have the defect of causing "warping"
to plate-like shaped articles prepared from plastics reinforced by
these materials.
In an attempt to remedy this defect, addition of scale-like mica
was suggested. The mica is effective for reducing the "warping" of
the plate-like shaped articles. However, it scarcely reduces
"warping", or rather increases it, when contained in ribbed shaped
articles or box-like shaped articles. Moreover, shaped articles
containing mica have the defect of low impact strength and of
marked coloration ascribable to mica. It has been desired therefore
to provide a polyester resin composition which can afford shaped
articles being free from warping and having superior mechanical and
thermal properties and a good color.
The present inventors, as a result of their efforts to provide such
a polyester resin composition, found that a composition comprising
an aromatic polyester and a specified amount of flat glass flakes
can meet these requirements to some extent. They, however, noted
that shaped articles from this composition do not have entirely
satisfactory mechanical and thermal properties, and are still
desired to be improved. Further investigations finally led to the
discovery that the mechanical and thermal properties of such shaped
articles can be improved greatly by further adding a specified
amount of a specific epoxy compound to such a composition.
Thus, according to this invention, there is first provided a
polyester composition comprising 100 parts by weight of an aromatic
polyester, 5 to 150 parts by weight of flat glass flakes, and 0.01
to 10% by weight, based on the total weight of these two
ingredients, of an epoxy compound.
The flat glass flakes used in this invention, after having been
incorporated in the polyester resin, have a long diameter of not
more than 1,000 microns, preferably 1 to 500 microns, and an aspect
ratio, defined as the ratio of the long diameter to thickness, of
at least 5, preferably at least 10, especially at least 20. Glass
flakes commercially available may be used, and sometimes, they
undergo some pulverization when being mixed with the polyester
resin.
When the long diameter of the glass flakes exceeds 1,000 microns,
it is difficult to mix them uniformly with the resin, and the
properties of shaped articles prepared from the resulting resin
composition are variable. Glass flakes having an aspect ratio of
less than 5 do not have an effect of increasing the heat distortion
temperature of the polyester resin.
The amount of the flat glass flakes used is 5 to 150 parts by
weight, preferably 20 to 100 parts by weight, per 100 parts by
weight of the aromatic polyester. Amounts smaller than 5 parts by
weight cannot sufficiently achieve the effect of this invention.
When the amount exceeds 150 parts by weight, the glass flakes are
difficult to mix uniformly with the polyester, and the moldability
of the polyester composition is reduced. When the amount of the
glass flakes exceeds 100 parts by weight, the flow characteristics
of the resin are reduced during the shaping of the resin
composition. Accordingly, it is desirable to exercise a full
control over the shaping conditions.
Up to one half of the flat glass flakes can be replaced by a
powdery inorganic solid. This replacement is desirable because not
only can it reduce the cost of production, but also it can increase
the weld strength ratio (the ratio of the tensile strength of a
shaped article having a weld to that of a shaped article containing
no weld) of the shaped article. When more than one half of the flat
glass flakes is replaced by the powdery inorganic solid, the weld
strength ratio rather decreases. The powdery inorganic solid
broadly includes fillers which are usually added to resins or
rubbers to extend them, adjust their viscosities, or to improve
their properties. Examples of this inorganic solid are calcium
carbonate, titanium oxide, feldspar (for example, Minex sold by
shiraishi Kogyo K.K.), clay, white carbon, carbon black, kaolin
clay, and talc. The particle size of the inorganic solid is not
particularly critical, and may be those of commercially available
solids. However, it is preferably 1 to 50 microns, and inorganic
solids having an average particle diameter of not more than 30
microns are especially preferred.
The aromatic polyester used in this invention is typically a
polyester derived from terephthalic acid as an acid component and
at least one aliphatic diol containing 2 to 10 carbon atoms such as
ethylene glycol, trimethylene glycol, tetramethylene glycol,
hexamethylene glycol or neopentyl glycol as a glycol component.
Polytetramethylene terephthalate, polypropylene terephthalate and
polyethylene terephthalate which have a fast rate of
crystallization are among preferred aromatic polyesters for use in
this invention. Polytetramethylene terephthalate is especially
preferred.
Products resulting from the partial replacement of the molecules of
such aromatic polyesters by a comonomer component can also be used
in this invention. Examples of such a comonomer include phthalic
acids such as isophthalic acid and orthophthalic acid;
alkyl-substituted phthalic acids such as 3-methylterephthalic acid
and 4-methylisophthalic acid; naphthalenedicarboxylic acids such as
2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid
and 1,5-naphthalenedicarboxclic acid; diphenyldicarboxylic acids
such as 4,4'-diphenyldicarboxylic acid and
3,4'-diphenyldicarboxylic acid; other aromatic dicarboxylic acids
such as 4,4'-diphenoxyethanedicarboxylic acid; aliphatic or
alicyclic dicarboxylic acids such as succinic acid, adipic acid,
sebacic acid, azelaic acid, decanedicarboxylic acid and
cyclohexanedicarboxylic acid; alicyclic diols such as
1,4-cyclohexanedimethanol; dihydroxybenzenes such as hydroquinone
and resorcinol; bisphenols such as 2,2-bis(4-hydroxyphenyl)propane
and 2,2-bis(4-hydroxyphenyl)sulfone; aromatic diols such as an
ether diol derived from a bisphenol (e.g.,
2,2-bis(4-hydroxyphenyl)propane) and a glycol (e.g., ethylene
glycol); and hydroxycarboxylic acids such as
.epsilon.-hydroxycaproic acid, hydroxybenzoic acid and
hydroxyethoxybenzoic acid.
Also useful in this invention are products obtained by
copolymerizing not more than 1.0 mole%, preferably not more than
0.5 mole%, more preferably not more than 0.3 mole% of a tri- or
tetra-functional ester-forming acid such as tricarballylic acid,
trimesic acid or trimellitic acid or a tri- or tetra-functional
ester-forming alcohol such as glycerol, trimethylol propane or
pentaerythritol.
Desirably, the aromatic polyester used in this invention has a
reduced viscosity (.eta..sub.sp/c) of at least 0.70, preferably at
least 0.80, especially at least 0.90. The reduced viscosity is
measured in ortho-chlorophenol at 35.degree. C. in a concentration
of 1.2 g/100 ml. The aromatic polyesters can be prepared by
ordinary methods, for example melt polycondensation, or a
combination of it with solid-phase polymerization. For example,
polytetramethylene terephthalate can be produced by reacting
terephthalic acid or its ester-forming derivative such as a lower
alkyl ester thereof (e.g., dimethyl ester or monomethyl ester) with
tetramethylene glycol or its ester-forming derivative under heat in
the presence of a catalyst, and polymerizing the resulting glycol
ester of terephthalic acid in the presence of a catalyst until the
desired degree of polymerization is reached.
The epoxy compound used in this invention may be any epoxy compound
containing two epoxy groups, and known epoxy ethers and epoxy
esters can be used. Epoxy compounds containing one epoxy group have
been found to be useless in improving mechanical and thermal
properties. Use of epoxy compounds containing three or more epoxy
groups can improve mechanical and thermal properties, but under
excessive heat, the polyester tends to assume a three dimensional
structure and therefore has reduced moldability. Furthermore, the
surface characteristics of shaped articles prepared from it will be
impaired. Typical examples of the epoxy compound used in this
invention are bisphenol-type epoxy compounds, novolak-type epoxy
compounds and aliphatic epoxy compounds. Diglycidyl polyether
(mono- to deca-mers) obtained by the reaction of
2,2-bis(4-hydroxyphenyl)propane (bisphenol A) with epichlorohydrin,
and diglycidyl ether obtained by the reaction of a glycol with
epichlorohydrin are especially preferred.
The amount of the epoxy compound to be added is 0.01 to 10 parts by
weight based on the total weight of the aromatic polyester and the
flat glass flakes.
The composition of this invention comprising the aromatic
polyester, the flat glass flakes (and powdery inorganic solid) and
the epoxy compound gives shaped articles being free from "warping"
and having greatly improved mechanical and thermal properties.
However, depending upon its constituents and their proportions, the
composition may have insufficient stability in the molten state.
For example, when the residence time is prolonged even a little in
the melt kneading of the composition by an extruder, an injection
molding machine, etc. the melt viscosity of the composition changes
drastically. As a result, the extrusion stability of the
composition may be impaired, or its flowability may be decreased
drastically, resulting in shaped articles having poor appearance.
The present inventors have found that the stability of the
composition in the molten state can be improved by incorporating
0.01 to 5%, based on the total weight of the aromatic polyester and
the flat glass flakes, of a certain phosphorus compound into the
composition. Accordingly, as one modification, the present
invention also provides a composition comprising 100 parts by
weight of an aromatic polyester, 5 to 150 parts by weight of flat
glass flakes (up to one half of the flakes can be replaced by a
powdery inorganic solid), and 0.01 to 10%, based on the total
weight of said ingredients, of an epoxy compound containing two
epoxy groups, and 0.01 to 5%, on the same basis, of a phosphorus
compound.
Examples of the phosphorus compound are phosphoric acid; phosphoric
esters such as trimethyl phosphate, methyldiethyl phosphate,
triethyl phosphate, triisopropyl phosphate, tributyl phosphate,
triphenyl phosphate, tribenzyl phosphate, or tricyclohexyl
phosphate; phosphorous acid; phosphorous acid esters such as
trimethyl phosphite, triethyl phosphite, tributyl phosphite,
tri(.delta.-hydroxybutyl) phosphite or triphenyl phosphite;
phosphonic acid; phosphonic acid derivatives such as phenyl
phenylphosphonate, diphenyl phenylphosphonate or phenyl
phosphonate; phosphinic acid; phosphinic acid derivatives such as
phenylphosphinic acid, methyl dimethylphosphinate, phenyl
methylphosphinate or triphenyl phosphine; triphenyl phosphine
oxide; and metal phosphates such as monosodium phosphate,
monopotassium phosphate or monolithium phosphate. These phosphorus
compounds may be used singly or as a mixture of two or more.
Since the flat glass flakes are composed of various inorganic
oxides, they can function fully as a ring-opening catalyst for the
epoxy compound. In addition, because the composition of this
invention is exposed to very high temperatures during melt kneading
in an extruder or an injection molding machine, the reaction of the
epoxy compound proceeds further. The phosphorus compound is
believed to act in a way to inhibit the excessive progress of the
reaction of the epoxy compound. When the flat glass flakes are
weakly alkaline, they will exert undesirable effects on the
aromatic polyester (for example, reduce the mechanical properties
of the polyester). The phosphorus compound is believed to alleviate
these effects, too.
When it is desired to further improve the impact strengths and tap
strengths of polyester shaped articles, the composition of this
invention may be incorporated with a rubbery elastomer selected
from copolymers containing 30 to 90% of an acrylic ester as a
constituent monomer and poly(ether. ester)elastomers. Accordingly,
as another modification, the present invention provides a
composition comprising 100 parts by weight of an aromatic
polyester, 5 to 150 parts by weight of flat glass flakes (up to a
half of the flakes can be replaced by a powdery inorganic solid),
and based on the total weight of said ingredients, (0.01 to 5% of a
phosphorus compound and) 0.5 to 5% of a rubbery elastomer.
Specifically, the copolymer containing 30 to 90% of an acrylic
ester as a constituent monomer denotes a graft copolymer, random
copolymer or block copolymer composed of 30 to 90% of an alkyl
acrylate with the alkyl group containing 1 to 13 carbon atoms and
70 to 10% of a vinyl monomer such as a lower alkyl methacrylate,
styrene, acrylonitrile, triallyl isocyanurate, or allyl
methacrylate.
The poly(ether.ester)elastomer is an elastomer derived from (1) a
dicarboxylic acid and/or its ester-forming derivative, (2) a
low-molecular-weight glycol and/or its ester-forming derivative,
and (3) a polyoxyalkylene glycol having an average molecular weight
of 500 to 5,000 and/or its ester-forming derivative, in which the
polyester derived from components (1) and (2) has a melting point
of at least 140.degree. C., and the unit derived from component (3)
accounts for 5 to 95% by weight of the entire polymer.
Typically, the component (1) is an aromatic dicarboxylic acid.
Examples of preferred aromatic dicarboxylic acids are terephthalic
acid, isophthalic acid, naphthalenedicarboxylic acids,
diphenylcarboxylic acid, diphenylsulfonedicarboxylic acid,
diphenoxyethanedicarboxylic acid, diphenylether dicarboxylic acid,
methylterephthalic acid, and methylisophthalic acid. Terephthalic
acid is especially preferred. A part, preferably not more than 30
mole%, more preferably not more than 20 mole%, of the component (1)
may be replaced by another dicarboxyolic acid. Examples of other
dicarboxylic acids include aliphatic dicarboxylic acids such as
succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid
or dimeric acid, alicyclic dicarboxylic acids such as
hexahydroterephthalic acid, and hydroxycarboxylic acids such as
.epsilon.-hydroxycaproic acid, hydroxybenzoic acid or
hydroxyethoxybenzoic acid. The ester-forming derivatives of the
dicarboxylic acids can also be used as the component (1). Examples
are lower alkyl esters, aryl esters and acid halides of
dicarboxylic acids.
Examples of the low-molecular-weight glycol as component (2) are
ethylene glycol, trimethylene glycol, tetramethylene glycol,
neopentylene glycol, hexamethylene glycol, decamethylene glycol,
cyclohexanedimethylol, 2,2-bis(.beta.-hydroxyethoxyphenyl)propane,
hydroquinone, and 2,2-bis(hydroxyphenyl)propane. Tetramethylene
glycol is especially preferred. The ester-forming derivatives of
the low-molecular-weight glycols can also be used as the component
(2). Examples are lower fatty acid esters of the glycols, and
ethylene oxides of the glycols.
Examples of suitable polyoxyalkylene glycols as component (3) are
polyethylene glycol, polypropylene glycol, polytrimethylene glycol,
polytetramethylene glycol and copolymers of two or more of these.
Polytetramethylene glycol is especially preferred. The
ester-forming derivatives of polyoxyalkylene glycols can also be
used as component (3). Examples are lower fatty acid esters of
these polyoxyalkylene glycols. The polyoxyalkylene glycol as
component (3) has an average molecular weight of 500 to 5,000,
preferably 600 to 4,000, more preferably 800 to 3,000. The
proportion of the polyoxyalkylene glycol to be copolymerized is
desirably 5 to 95% by weight, preferably 5 to 85% by weight, more
preferably 10 to 80% by weight, especially preferably 15 to 75% by
weight.
When the amount of the rubbery elastomer is less than 0.5% based on
the total weight of the aromatic polyester and the flat glass
flakes, the intended effect is small, and when it exceeds 50%, the
rigidity of shaped articles is reduced.
The polyester composition of this invention can be produced by
mixing the required ingredients. For example, the flat glass flakes
and the epoxy compound and as optional ingredients, the powdery
inorganic solid, the phosphorus compound and/or the rubbery
elastomer are added to the molten aromatic polyester and mixed. Or
a method can be employed which comprises mixing the aromatic
polyester chips, the flat glass flakes and the epoxy compound and
optionally, the powdery inorganic solid, phosphorus compound and/or
elastomer, and effecting further mixing under melting conditions.
Prior to use, the flat glass flakes (and powdery inorganic solid)
may be surface-treated with a coupling agent.
The polyester composition of this invention may include ordinary
additives such as nucleating agents, lubricants, antioxidants,
ultraviolet light absorbers, heat stabilizers, pigments and
modifiers other than epoxy compounds in amounts which do not impair
the objects of this invention. Other thermoplastic resins or
thermosetting resins may also be incorporated into the composition
of this invention. These compounds can be added at any desired
stage in the production of the polyester.
Furthermore, fire-retarding additives may be incorporated into the
polyester composition of this invention. Such additives are
composed of fire retardants or a combination of them with fire
retardant aids. The fire retardants are, for example, compounds
containing halogen, phosphorus, nitrogen, etc. such as organic
halogen compounds and phosphorus compounds. The fire retardant aids
are, for example, compounds of metals of Group Vb of the periodic
table. A number of compounds useful as fire retardants and fire
retardant aids have been known heretofore, and they can also be
used in this invention. Suitable fire retarding additives are
mixtures of organic or inorganic antimony compounds (for example,
antimony trioxide) and organic halogen compounds (especially
brominated or chlorinated organic compounds), especially a mixture
of antimony trioxide and a carbonate of a halogenated bisphenol or
its oligomer. Preferred carbonates of halogenated bisphenol or
oligomers thereof are those having the following structure ##STR1##
wherein R.sub.1 and R.sub.2 each represent a hydrogen atom, an
alkyl group containing 1 to 4 carbon atoms, or a phenyl group,
X.sub.1 X.sub.2 represent a bromine or chlorine atom, and m and n
are numbers of 1 to 4; and having an average degree of
polymerization of 2 to 30, preferably 2 to 25. In the above
formula, the terminal groups may be any organic groups such as
phenyl, substituted phenyl or alkyl. Since the flat glass flakes
(and the powdery inorganic solid) are incombustible, a sufficient
fire retarding effect can be obtained by incorporating the fire
retardant in an amount of 10 to 50 parts by weight, preferably 15
to 30 parts by weight, per 100 parts by weight of the polyester
composition.
The polyester composition of this invention gives shaped articles
which are free from warping and have a high heat distortion
temperature and superior mechanical properties and dimensional
stability. By taking advantage of these merits, the polyester
composition of this invention is useful in automobiles, electric
appliances, mechanical devices and instruments, especially in
small-sized structural component parts such as watches and
cameras.
The following Examples taken in conjunction with Controls
illustrate the present invention in greater detail. All parts in
these examples are by weight.
EXAMPLES 1 TO 7 AND CONTROLS 1 TO 6
To 100 parts of polytetramethylene terephthalate having a reduced
viscosity (.eta..sub.sp/c) of 1.15 were added the flat glass flakes
and epoxy compounds shown in Table 1 in the amounts indicated. Each
of the mixtures was melt-kneaded and extruded at a cylinder
temperature of 250.degree. C. using an extruder having a screw
diameter of 65 mm to form pellets. The pellets were molded by an
injection molding machine to form samples suitable for the ASTM
testing methods shown in Table 1, and the samples were evaluated.
The results are shown in Table 1.
In the Controls, the epoxy compound was omitted, or mica was used
instead of the glass flakes. Otherwise, the same procedure as above
was repeated. The results are also shown in Table 1.
TABLE 1
__________________________________________________________________________
Flexural Epoxy characteristics Heat dis- compound Impact strength
Tensile characteristics ASTM D 790 tortion temp. Filler Type ASTM D
256 ASTM D 638 Modulus ASTM D 648 Ex- Amount [Amount 1/4 inch 1/8
inch Strength Elongation Strength elasticity 264 psi ample Type
(parts) (parts)] (kg cm/cm) (kg cm/cm) (kg/cm.sup.2) (%)
(kg/cm.sup.2) (kg/cm.sup.2) (.degree.C.)
__________________________________________________________________________
Flat glass *Epikote 5.4 5.7 630 3.3 980 44,000 130 (Ex.) 1 flakes
20 815 (0.8) (aspect ratio 20-50) Flat glass *Epikote Ex. 2 flakes
40 815 (0.8) 5.0 5.5 720 3.2 1,100 62,000 166 (aspect ratio 20-50)
Flat glass *Epikote Ex. 3 flakes 70 815 (0.8) 4.9 5.1 850 3.0 1,300
90,000 190 (aspect ratio 20-50) Flat glass *Epikote Ex. 4 flakes
100 815 (0.8) 4.8 4.6 990 2.8 1,480 119,000 202 (aspect ratio
20-50) Flat glass Epikote Ex. 5 flakes 70 815 (0.1) 5.0 5.0 820 3.0
1,250 89,000 203 (aspect ratio 20-50) Flat glass Epikote Ex. 6
flakes 70 815 (2.0) 4.8 4.9 870 2.9 1,360 90,500 200 (aspect ratio
20-50) Flat glass **Denacol Ex. 7 flakes 70 EX-820 5.2 5.3 840 3.1
1,280 88,500 201 (aspect ratio (1.0) 20-50) Flat glass Con- flakes
20 None 4.7 5.4 590 2.9 920 42,500 134 trol 1 (aspect ratio 20-50)
Flat glass Con- flakes 40 None 4.2 4.8 645 2.7 990 61,000 169 trol
2 (aspect ratio 20-50) Flat glass Con- flakes 70 None 3.5 3.9 720
2.3 1,090 89,000 192 trol 3 (aspect ratio 20-50) Flat glass Con-
flakes 100 None 2.8 3.0 800 2.1 1,190 116,000 204 trol 4 (aspect
ratio 20-50) Con- ***Mica Epikote trol 5 (No. 3) 70 815 (0.8) 3.2
3.4 730 1.6 1,030 114,000 194 Con- ***Mica trol 6 (No. 3) 70 None
2.9 3.3 715 1.5 1,000 117,000 195
__________________________________________________________________________
*Epoxy resin made by Shell Chemical Co. **Epoxy resin made by
Nagase Sangyo K.K. ***Mica made by Osaka Mica Kogyo K.K.
As is clearly seen from the results shown in Table 1, the shaped
articles prepared from the compositions of this invention have very
high impact strength, tensile strength and flexural strength. In
contrast, the shaped articles prepared from the compositions not
containing the epoxy compound are inferior in the aforesaid
properties. When mica is used instead of the glass flakes, the
mechanical strength of a shaped article prepared from the
composition containing the epoxy compound is not much different
from that of a shaped article prepared from the composition not
containing the epoxy compound. In other words, when mica is added,
there is hardly any increase in the mechanical strength of shaped
articles by the addition of the epoxy compound as intended by the
present invention.
Each of the compositions of Example 3 and Control 3 was molded into
discs having a thickness of 1/16 inch and a diameter of 4 inches by
an injection molding machine. Each of the discs was placed on a
flat table made of precision cast iron, and the maximum clearance
between the table surface and the disc was measured by a height
gauge. In the shaped article of Example 3, the clearance was 0.05
mm, while in the shaped article of Control 3, it was 0.08 mm.
Hence, the shaped article obtained in Example 3 had less
warping.
Test pieces for tensile testing in accordance with ASTM D-638 were
prepared from the compositions of Example 3 and Control 3. These
test pieces were placed in a Geer's aging tester at 185.degree. C.
for the periods indicated in Table 2, and then their tensile
strengths were measured. The results are shown in Table 2.
TABLE 2 ______________________________________ Tensile strength
(kg/cm.sup.2) After 5 days After 10 days After 20 days
______________________________________ Example 3 935 810 580
Control 3 710 520 360 ______________________________________
It is seen from Table 2 that the shaped article from the
composition of this invention has very good thermal stability.
EXAMPLES 8 TO 12 AND CONTROLS 7 TO 12
To 100 parts of polytetramethylene terephthalate having a reduced
viscosity (.eta..sub.sp/c) of 1.50 were added the flat glass
flakes, the powdery inorganic solids and epoxy compounds shown in
Table 3 in the amounts indicated. Each of the mixtures was
melt-kneaded and extruded at a cylinder temperature of 250.degree.
C. by using an extruder with a screw diameter of 65 mm to form
pellets.
The pellets were molded by an injection molding machine to form
molded pieces suitable for the ASTM testing methods shown in Table
3. The molded pieces were tested, and the results are shown in
Table 3.
Molded pieces having a weld were produced by molding in a mold for
ASTM D-638 consisting of a dumbbell and a gate at both ends adapted
to generate a weld forcible at the central part of the
dumbbell.
In the Controls, the epoxy compound was omitted or glass fibers
were used instead of the glass flakes. Otherwise, the same
procedure as above was repeated, and the results are also shown in
Table 3.
TABLE 3
__________________________________________________________________________
Flat glass flakes (aspect Tensile characteristics Flexural
characteristics ratio ASTM D-638 Weld ASTM D-790 Ex- 20-50) Powdery
inorganic solid Epoxy compound Strength Elongation strength
Strength Modulus of elasticity ample (parts) [Amound (parts)]
[Amound (parts)] (kg/cm.sup.2) (%) ratio (kg/cm.sup.2)
(kg/cm.sup.2)
__________________________________________________________________________
***Epikote 8i5 (Ex.) 8 35 *Minex 7 (35) (2.5) 690 4.5 0.85 1,200 65
.times. 10.sup.3 Ex. 9 50 Minex 7 (15) Epikote 815 (2.5) 760 4.0
0.81 1,300 75 .times. 10.sup.3 Ex. 10 15 Minex 7 (15) Epikote 815
(2.5) 610 5.5 0.90 1,000 45 .times. 10.sup.3 Ex. 11 35 Calcium
carbonate (35) Epikote 815 (4.0) 670 3.7 0.84 1,150 65 .times.
10.sup.3 Ex. 12 35 Kaolin clay (35) ****Denacol EX-810 660 3.5 0.83
1,140 64 .times. 10.sup.3 (0.5) Con- trol 7 50 Minex 7 (15) None
660 3.2 0.48 1,100 73 .times. 10.sup.3 Con- trol 8 95 Minex 7 (60)
Epikote 815 (2.5) 900 3.0 0.37 1,480 93 .times. 10.sup.3 Con- trol
9 60 Minex 7 (95) Epikote 815 (2.5) 710 3.3 0.38 1,230 70 .times.
10.sup.3 Con- trol 10 **Glass Minex 7 (35) Epikote 815 (2.5) 1,200
3.5 0.35 1,800 80 .times. 10.sup.3 fiber 35 Con- trol 11 35 Calcium
carbonate (35) None 580 3.1 0.77 1,040 64 .times. 10.sup.3 Con-
trol 12 35 Kaolin clay (35) None 575 2.9 0.77 1,010 64 .times.
10.sup.3
__________________________________________________________________________
*a feldspar type mineral sold by Shiraishi Kogyo K.K. **chopped
strand, fiber length 3 mm ***Epoxy resin made by Shell Chemical Co.
****Epoxy resin made by Nagase Sangyo K.K.
The results given in Table 3 demonstrate that the shaped articles
prepared from the compositions of this invention have a very high
weld strength ratio and superior tensile strength and flexural
strength. In contrast, the shaped article prepared from the
composition of Control 7 which does not contain the epoxy compound
has a far lower weld strength ratio and lower tensile strength and
flexural strength than the shaped article prepared from the
composition of Example 9.
The shaped articles prepared from the compositions of Controls 8
and 9 which contain the flat glass flakes or the powdery inorganic
solid in amounts exceeding the specified ranges in this invention
have a far lower weld strength ratio.
The shaped article prepared from the composition of Control 10
containing glass fibers instead of the flat glass flakes has higher
tensible strength and flexural strength but far lower weld strength
ratio than the shaped article prepared from the composition of
Example 8. The absolute value of the tensile strength of a
weld-containing shaped article was 587 kg/cm.sup.2 in Example 8,
but as low as 420 kg/cm.sup.2 in Control 10.
Discs having a thickness of 1/16 inches and a diameter of 4 inches
were prepared by an injection molding machine from the compositions
of Example 8 and Control 10. The discs were placed on a flat table
made of precision cast iron, and the maximum clearance between the
table surface and the disc was measured by a height gauge. It was
0.04 mm in Example 8, but 7.2 mm in Control 10, showing that the
shaped article of Example 8 has very much reduced warping.
Test pieces for tensile testing in accordance with ASTM D-638 were
prepared from the compositions of Examples 9, 11 and 12 and
Controls 7, 11 and 12, and were each placed in a Geer's aging
tester at 185.degree. C. for the periods indicated in Table 4.
Then, the tensile strengths of these pieces were measured, and the
results are shown in Table 4.
TABLE 4 ______________________________________ Tensile strength
(kg/cm.sup.2) After 5 days After 10 days After 20 days
______________________________________ Example 9 805 735 515
Example 11 705 650 470 Example 12 685 615 435 Control 7 665 475 330
Control 11 575 430 300 Control 12 560 405 275
______________________________________
It is seen from the results shown in Table 4 that the shaped
articles from the compositions of this invention have very good
thermal stability.
EXAMPLES 13 TO 15 AND CONTROLS 13 TO 15
To 100 parts of polytetramethylene terephthalate having a reduced
viscosity (.eta..sub.sp/c) of 1.50 were added the flat glass
flakes, the epoxy compounds and phosphorus compounds and optionally
the powdery inorganic solid or Kaneace FM (a trademark for an
acrylic graft copolymer produced by Kanegafuchi Chemical Industry
Co., Ltd.) shown in Table 5 in the amounts indicated. Each of the
mixtures was melt-kneaded and extruded at a cylinder temperature of
260.degree. C. by an extruder having a screw diameter of 65 mm to
form pellets.
The pellets were injection-molded, and the properties of the molded
articles were measured. The results are shown in Table 5.
In the Controls, the phosphorus compound was omitted, and
otherwise, the same procedure as above was repeated. The results
are also shown in Table 5.
TABLE 5
__________________________________________________________________________
Example 13 Control 13 Example 14 Control 14 Example 15 Control
__________________________________________________________________________
15 Resin Amount of flat glass flakes 70 70 35 35 35 35 formu-
(aspect ratio 20-50) (parts) lation Epoxy Type *Epikote Epikote
**Denacol Denacol Epikote Epikote compound 815 815 EX-810 EX-810
828 828 Amount (parts) 0.5 0.5 4.0 4.0 2.5 2.5 Phosphorus Type
Trimethyl -- Sodium -- Tributyl -- compound phosphite mono-
phosphate phosphate Amount (parts) 0.2 -- 0.5 -- 1.0 -- Powdery
Type -- -- Calcium Calcium *** Minex 7 inorganic carbonate
carbonate Minex 7 solid Amount (parts) -- -- 35 35 35 35 ****Amount
of Kaneace FM -- -- -- -- 9 9 (parts) Flowability At the start of
molding (cm) 36 35 30 29 32 31 At the 5th shot (cm) 36 34 30 26 32
29 At the 10th shot (cm) 37 32 31 22 32 28 At the 15th shot (cm) 38
29 32 18 33 26 At the 20th shot (cm) 38 26 32 15 34 25 Tensile
strength (ASTM D-638, 849 853 668 660 600 610 kg/cm.sup.2) Break
elongation 3.1 2.9 3.1 3.0 6.4 4.7 (ASTM D-638, %) Flexural
strength 1,310 1,290 1,137 1,140 1,005 1,013 (ASTM D-790,
kg/cm.sup.2) Flexural modulus (ASTM D-790, 89,000 90,000 64,000
65,000 52,700 53,200 kg/cm.sup.2)
__________________________________________________________________________
*Epoxy resin made by Shell Chemical Co. **Epoxy resin made by
Nagase Sangyo K.K. ***Feldspar mineral sold by Shiraishi Kogyo K.K.
****Rubbery copolymer made by Kanegafuchi Chemical Industry Co.,
Ltd.
In Table 5, the flowability of each composition was determined by
molding the composition by an injection molding machine having a
spiral mold (with a thickness of 3 mm and a width of 10 mm in cross
section) while maintaining the cylinder temperature at 250.degree.
C., the mold temperature at 60.degree. C., and the injection
pressure at 1,000 kg/cm.sup.2 ; and comparing the spiral lengths
measured at the start of molding, the 5th shot, the 10th shot, the
15th shot, and the 20th shot.
As is clear from the results shown in Table 5, the variations in
spiral length (i.e., the variations in flowability) from shot to
shot are very little in the compositions of this invention. This
means that the compositions of this invention have very good
stability in the molten state. In contrast, in the compositions of
the Controls, the absolute values of spiral length are low, and the
spiral length becomes shorter progressively from shot to shot. This
means that by the residence of the compositions in the cylinder,
their flowabilities change, namely these compositions have poor
stability in the molten state.
Discs, 1/16 inch thick and 4 inches in diameter, were prepared from
the compositions of this invention. All of these discs were found
to be substantially free from "warping".
EXAMPLE 16 AND CONTROLS 16 AND 17
To 100 parts by weight of polytetramethylene terephthalate having a
reduced viscosity (.eta..sub.sp/c) of 1.22 were added 15 parts by
weight of flat glass flakes (aspect ratio of 30-50) and, powdery
feldspar (Minex-7, a trademark for a product of Indusmin Company)
and a polytetramethylene terephthalate-type block copolymer (HYTREL
4055, a trademark for a product of Du Pont) as a
poly(ether.ester)elastomer in the amounts indicated in Table 6.
Each of the mixtures was melt-kneaded and extruded at a cylinder
temperature of 240.degree. C. by an extruder having a screw
diameter of 50 mm to form chips.
The chips were injection-molded by using a 1-ounce injection
molding machine under the following conditions.
Molding temperature: 240.degree. C.
Molding cycle: primary pressure (hydraulic pressure: 80
kg/cm.sup.2) 2 seconds; secondary pressure (hydraulic pressure: 50
kg/cm.sup.2) 8 seconds; and cooling time 25 seconds.
Mold temperature: 60.degree. C.
The impact strengths (thickness: 1/4 inch pieces, both notched and
unnotched) and tap strengths of the molded articles were measured.
The tap strength was measured by a simplified method which
comprises providing a hole with a diameter of 4 mm in a 1/4 inch
test piece by a drilling machine, screwing a wooden screw having an
outside diameter of 4.5 mm and a length of 5 cm into the hole, and
measuring the length (cm) of the wooden screw which could be
inserted until the shaped article was broken. The larger this value
is, the higher is the tap strength.
Flat plates, 9.90 cm in length, 10.35 cm in width, and 0.2 cm in
thickness, were prepared by using an in-line screw type injection
molding machine made by Nikko Anker (3.5 ounces), and the percent
molding shrinkages of the resulting flat plates wee measured. When
the percent molding shrinkages in the longitudinal and transverse
directions are more approximate to each other (that is, when the
ratio of the percent shrinkages more approaches 1.0), the warping
of the shaped article is smaller, and therefore, stress in shaped
articles of various configurations is less. The results are shown
in Table 6.
TABLE 6
__________________________________________________________________________
Properties of molded articles Amount (% by weight) Percent molding
Epoxy Impact strength Tap shrinkage (%) Ratio of Powdery compound
(1/4inch) strength Longi- Trans- percent feldspar Elastomer (*)
Notched Unnotched (cm) tudinal verse shrinkages
__________________________________________________________________________
Ex- ample 15 5 0.5 5.2 75.2 1.01 1.35 1.69 1.25 16 Con- trol 15 5
-- 5.1 71.5 0.95 1.38 1.73 1.25 16 Con- trol 15 -- -- 4.6 50.0 0.75
1.40 1.75 1.25 17
__________________________________________________________________________
(*): Denacol EX314 (a trademark for glycerol polyglycidyl ether
made by Nagase Sangyo K.K.)
As is clearly seen from the results shown in Table 6, the shaped
article from the polyester composition of this invention has
markedly increased impact strength and tap strength.
EXAMPLE 17 AND CONTROLS 18 AND 19
To 100 parts of polytetramethylene terephthalate having a reduced
viscosity (.eta..sub.sp/c) of 1.22 were added powdery feldspar
(Minex-7, trademark), flat glass flakes (Glass Flake CF 48, a
trademark for a product of Nippon Glass Fibers K.K.) and the same
poly(ether.ester)elastomer as used in Example 16 in the amounts
indicated in Table 7. Each of the mixtures was melt-kneaded and
extruded at a cylinder temperature of 240.degree. C. by using an
extruder with a screw diameter of 50 mm to form chips.
The chips were injection molded by a 1-ounce injection molding
machine under the following conditions.
Molding temperature: 240.degree. C.
Molding cycle: primary pressure (hydraulic pressure: 80
kg/cm.sup.2) 2 seconds; secondary pressure (hydraulic pressure: 50
kg/cm.sup.2) 8 seconds; and the cooling time 25 seconds.
Mold temperature: 60.degree. C.
The impact strengths (1/4 inch thick test pieces, both notched and
unnotched), tap strengths (the same as in Example 16) and heat
distortion temperatures (1/4 inch test pieces under a load of 264
psi) of the molded articles were measured.
Flat plates, 9.90 cm in length, 10.35 cm in width and 0.20 cm in
thickness, were prepared by using an in-line screw type injection
molding machine (3.5 ounces, made by Nikko Anker), and the percent
molding shrinkages of the flat plates were measured.
The results are shown in Table 7.
TABLE 7
__________________________________________________________________________
Properties of molded articles Percent Heat Amounts added (parts)
molding dis- Epoxy shrinkage (%) Ratio tor- com- Impact strength
Tap Longi- of tion Powdery Glass pound (1/4") strength tud- Trans-
shrink- temp. feldspar Elastomer flakes (*) Notched Unnotched (cm)
inal verse ages (.degree.C.)
__________________________________________________________________________
Ex- ample 10 5 20 0.5 5.6 81.4 1.13 1.33 1.50 1.13 104 17 Con- trol
10 5 20 -- 5.3 75.0 0.98 1.33 1.50 1.13 115 18 Con- trol 10 10 20
-- 5.4 77.9 1.04 1.13 1.28 1.21 102 19
__________________________________________________________________________
(*) Denacol EX314
It is seen from the above table that the polyester composition of
this invention gives a shaped article having superior impact
strength (notched, and unnotched), tap strength and heat distortion
temperature and reduced warping.
EXAMPLE 18
To 100 parts of polytetramethylene terephthalate having a reduced
viscosity (.eta..sub.sp/c) of 1.50 were added 80 parts of flat
glass flakes having an aspect ratio of 20 to 50, 10 parts of a
rubbery copolymer and 0.5 part of an epoxy compound (Denacol
EX-810, a trademark). The mixture was melt-kneaded and extruded at
a cylinder temperature of 250.degree. C. by using an extruder
having a diameter of 65 mm to form pellets.
Ten test pieces, 50 mm in width, 150 mm in length and 2 mm in
thickness, for impact strength testing were prepared from these
pellets, and tested in accordance with a ball falling test of JIS
K6745-1976. All of the ten test pices were not broken by a 1 kg
steel ball which was let fall from a height of 70 cm. This fact
means that the composition shaped article prepared from the
composition of this invention has very good impact strength.
Then, discs, 1/16 inch in thickness and 4 inches in diameter, were
prepared from the pellets. Warping was scarcely seen in the
discs.
The rubbery copolymer described above was prepared by the following
steps (a) and (b).
(a) A polymerization vessel was charged with 1 part of
disproportionated potassium rhodinate, 200 parts of water, 0.19
part of formaldehyde sodium sulfoxylate dihydrate, 0.005 part of
ferrous sulfate and 0.01 part of disodium
ethylenediaminetetraacetate, and they were heated at 60.degree. C.
in a stream of nitrogen. With stirring, a mixture consisting of 100
parts of butyl acrylate, 0.5 part of allyl methacrylate and 0.2
part of cumene hydroperoxide was added dropwise over the course of
5 hours. Furthermore the temperature was raised to 80.degree. C.,
and the reaction was performed at this temperature for 3 hours to
form a latex of polybutyl acrylate.
(b) A polymerization vessel was charged with 60 parts (as solids
content) of the resulting polybutyl acrylate latex, 1 part of
disproportionated potassium rhodinate, 200 parts of water
(including the water in the latex). 0.19 part of formaldehyde
sodium sulfoxylate dihydrate, 0.005 part of ferrous sulfate and
0.01 part of disodium ethylenediaminetetraacetate, and they were
heated to 70.degree. C. in a stream of nitrogen. With stirring, a
mixture consisting of 24 parts of methyl methacrylate, 8 parts of
styrene, 8 parts of acrylonitrile, 0.25 part of triallyl
isocyanurate and 0.2 part of cumene hydroperoxide was added
dropwise over the course of 2 hours. The temperature was raised
further to 80.degree. C., and the polymerization was continued at
this temperature for 3 hours. The resulting copolymer was washed
with water and dried in a customary manner to form the desired
copolymer as a powder.
* * * * *